This invention relates to underwater vision devices. Specifically, this invention relates to underwater vision devices worn directly on the eye cornea, as a contact type lens, which provides strong correction below the water surface to permit a wearer to see as well underwater as he would normally see in an air environment.
In the prior art underwater vision devices, separate lenses are spaced from the cornea of the eye in the manner of spectacles and have a surface upon them with an index of refraction that compensates for the path of light entering the eye to correct it so that it conforms to the path provided in air and has sufficient magnification so that the swimmer sees normally under the water.
In some of these prior art units, a lens has a refractive index that does not completely correct for the Abbe number and aberration in air nor correct for the Abbe number and aberration in water but has a value between the two values necessary for water and air correction so as to partly correct for each. Thus, it is useful either above the water or below the water.
The prior art types of underwater vision devices have disadvantages in that they are worn external to the eyeball, are unduly bulky, complex, and have a narrow field of vision. For example, several United States patents disclose underwater optical systems that utilize different types of optical media of varying refractive indexes. Some such patents are U.S. Pat. No. 2,008,530 to Wick, U.S. Pat. No. 2,088,262 to Grano, U.S. Pat. No. 3,040,616 to Simpson, U.S. Pat. No. 3,672,750 to Hagen, U.S. Pat. No. 3,976,364 to Lindemann, U.S. Pat. No. 2,730,014 to Ivanoff, U.S. Pat. No. 3,320,018 to Pepke, and U.S. Pat. No. 4,256,386 to Herbert.
A contact lens for use above water is disclosed in U.S. Pat. No. 1,929,228. This lens is formed by outer and inner thin transparent members which do not have substantial thickness but the contact lens does have a space between the outer and inner members to provide an additional interface that may correct the wearer's vision for refactive index and the Abbe number.